Method of and apparatus for gas analysis



Nov. 18, 1930. H. H. DOW

xETHoD oF AND APPARATUS Fok GAs ANALYSIS Filed July. 28, 192s INVENTOR. f/eferf dZ70W TTORNE LS.

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Patented Nov. 18, 1930 UNITED STATES PATENT OFFICE HERBERT H. DOW, OF MIDLAND, MICHIGAN, ASSIGNOR TO THE DOW CHEMICAL COM- i PANY, F MIDLAND, MICHIGAN, A CORPORATION 0F MICHIGAN METHOD QF AND APPARATUS'FOB GAS ANALYSIS Application led July 28, 1926. Serial No. 125,559.

This invention relates to the art of determining the proportions of constituents in gaseous mixtures, and more particularly where heavy= or light constituents are to be determined. For industrial uses, it is highly desirable to be able to readily determine the proportion of certain gases present in a discharge or feed, and thus without necessity of resort to elaborate and time-consuming procedure.

To the accomplishment of the foregoing and related ends, the invention, then, consists in the features hereinafter disclosed, and particularly pointed out in the'claims, the annexed drawing representing but one of'varif ous forms in which the principle of the'in- 4vention may be employed.

In said annexed drawing The sole ligure represents somewhat diagrammatically one form of embodiment of my lnvention.

'The reference character 1 in the drawing designates a nozzle, preferably mounted at 2 for a slight swinging movement' or adjust'- ment, and connected to a means of supply of a gas tobe determined, the means shown by way of illustration comprising a reciprocating pump 3 having a feed pipe 4 leading through a heat exchanger or equalizer 5 from a source of supply of the gas. Arranged to act in opposition to the jet 1 is another nozzle 6, also preferably mounted as at 7 for a slight swinging or adjustable movement, and connected by a pipe 8 to the pump 3 from which a pipe 9,

leads through the heat exchanger or equalizer 5 from the air. By arranging theiconnectio'ns for the gas on one side of the plunger or pis? ton of the pump 'and the connections for the air on the other, alternate blasts of gasand ofA air may be jetted through the respective nozzles. Arranged in the path ofthese nozzles is a movable member 10, preferably in the form of a bladed rotor orpaddle wheel, andv this connects through a train of gearing 11,

to which is fixed a pointer 15. The hub of the wheel 14 carries spaced set screws or adjusting. screws 16, these being arranged in relation to the pointer 15 so as to provide an adjustable lost-motion connection between the through the heat exchanger and thereby hav- 12, 13 to a gear wheel 14 loose upon a shaft wheel and pointer. A scale 17 is placed in relationl to the pointer so as to be applicable in connection therewith.

Adjustably fixed also upon the same shaft as the pointer is a cam`l8 which actuates the roller of an arm 19 pivoted as at 20 and provlded with a link 21 connecting with the noz- ,zle 1'. Adjusting screws 22 are arranged with the nozzle 6 so as to allow of setting of the nozzle with respect to the rotor 10 atthe angle of attack desired.

In operation, a gas to be tested, for Ninstance, a iue gas, is drawn through the heat exchanger 5 and pipe 4 to the pump 3 and is forcedyout by the stroke of the plunger as a blast through the nozzle l direct upon the blades of the rotor 10. The latter is correspondingly given a whirl which communioates through the gear train to the wheel 14, and with the setting vof the adjusting screws 16 for normal circumstances will occasion no movementA of the pointer 15 by reason of the lost-motion allowed. A blast of airis now supplied by the pump, being drawn 'I6 ing its temperature equalize'd with that of tlie gas to be tested, and the blast of air jetting against the rotor 10 effects a whirling motion of the latter in a direction opposite to themotion imparted by the blast of gas, and correspondingly the gear train will cause the wheel '14 to move back in pro ortion. Again with aVera e conditions, the ost-motion provided by t e screws 16w1l allow of movement of the wheel without ai'ecting the pointer `l5 or nozzle 1. When however the effective mass of the gas jetted out from nozzle 1', relatively increases, as for instance with an increased proportion of carbon diox-` ide in the iue gas, the movement of the rotor 10 occasioned b the gasblast will be relatively greater t an the movement occasioned by the air blast, and as a result the wheel 14 will over-run and will carry the pointer 15 correspondingly. With the cumulative ei5-- 95 fect of successive blasts ofgas, each blast causing its overrun of thev gear-14 with resultant motion of the pointer 15, the latter will thus show a proportional reading on the scale 17. On the contrary, if the eifective mass 100 of the gas as jetted from the vnozzle 1 be less than that of the air blasts from nozzle 6, the travel of wheel 14 caused by the gas blasts will be less than its reverse movement as occasioned by the air blasts, and correspondingly the pointer will be progressively* stepped around in the opposite direction. In each case, the resultant of the movements o'ccasioned by the gas to be tested and the air'respectively, is ultimately shown in the amount of over-run occasioned in the respective direction by the wheel 14 and the associated pointer 15.

The cam 18 also being moved with the pointer around gradually by the cumulative over-run in either direction as the case may be, raises or lowers the nozzle 1 so as to diminish or to increase its effective attack upon the rotor. In this manner a compensating effect may be obtained, which will arrest the motion of the pointer when the blast actions have become equalized.

Initially, the device must be calibrated and this may be conveniently accomplished by checking the content of the gas to be tested by means of chemical analysis, and a suitable number of oints having been determined for the scale, t e remainder can then be proportioned. In the first instance, the nozzle 6 is so adjusted by means of the screws 22 that the effective attack of the air blasts will just balance that of the gas jettedl from nozzle 1, at the point desired to be taken as normal or standard. In the scale illustrated, provision is made for gradations from zero to 16 major divisions corresponding to the customary range of carbon dioxide content in boiler flue gases. The particular gradations however, in any case will depend upon the requirements in hand and also fundamentally upon the ty e of gas being tested.

In t e adjusting of the device, assuming the pointer set at zero position and the flue gas pipe connected to the air instead oftothe source of flue gas, with the compressor being operated, the rotor 10 will be alternately turned backward and forward by the respec- -tive jets, and correspondingly there will be motion of the wheel 14. Adyustment of the screws 22 will regulate the relative effects upon the rotor so that the wheel 14 will oscillate back and forth over a consistent arc. If now, flue gas be admitted and discharged through nozzle 1, assuming that at the time no fuel is being burned, the conditions will be similar, and the pointer 15 will still be unaffected by the arc of movement of the wheel 14. If now combustion proceed in the furnace, the carbon dioxide content in the flue gas begins to manifest its effect in the greater mass as determined by the heavier gas, and the balanced effect upon the rotor will be upset, the jet of f'lue gas causing greater movement of the rotor, and the consequent traverse of the wheel 14 ina direction to cumulatively step up the pointer 15. At'the same time, the cam 118 will also be moved so as to progressively raise the nozzle 1, and such changes will proceed until the deflection of the nozzle 1 has reached a pointsuch that the rotative effect of its jet of flue gas is reduced to that of the jet of air, and the traverse of the gear wheel 14 and adjusting screws .16 will then be again over a fixed arc, and occasion no further movement of the pointer 15 as long as the content of carbon dioxide remains the same. By now marking the dial with the number corresponding to the analyzed content of carbon dioxide in the flue gas as found for instance by Orsat test and similarly locating other points under conditions of different carbon dioxide feed, a sufficient number can be provided to enable completion of calibration of the dial in terms of'percentage as desired.

lVith calibration and adjustment completed and the device operating, and indicating a carbon dioxide content of say 12 er cent., should the carbon dioxide content all for any reason, the immediate result would be to reduce the rotative effect of the flue gas jet as compared with the opposingair jet, and a progressive traverse of the gear wheel 14 and a corresponding. shifting of the pointer will occur to a new position of balance or stability, the pointer then indicating the existent percentage of carbon dioxide. Should the carbon dioxide content rise for any reason, reverse action will take place and correspondingly indicate the increased percentage of carbon dioxide.

The promptness with which indication is obtained and the accuracy will depend upon the precision of construction of the mechanical parts of the device and the period of oscillation chosen for the compressor.

It is seen therefore than the device when once properly calibrated will function automatically to indicate the carbon dioxide content of the flue gas. Any desired adaptation of the pointer may be applied, as well recognized in the art` It will also be seen that the device can be used as well for showing the sulphur dioxide content in burner gases or in fact to show the proportion of any gas in a mixture of gases, it being merely necessary in each such case to establish the proper adjustments of the nozzle to obtain a constant traverse of the gear so as to allow pointer indication at zero, and then calibrate by reference, by analyzing on sampling as the gas is supplied through the device.

lVhile the detail construction illustrated will in general be most convenient, the arrangement may be varied in particular details so long as two blasts of gas are provided so as to act alternately in opposition upon the movable member connected with the indicating or recording means.

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Instead of air as the gras ot constant quality supplied tctbe et opposing the et ot' gas to be tested, I also contemplate in some cases the use of other gases for this purpose, and by similarly equalizing the temperatiuc', the result in any instance is to allow ot measurement oi the effective mass in the gras tested. Other modes or" applying the principle ot the invention may be employed, change being made in the neatiues herein disclosed, provided the steps or means stated in an;Y of

the following c iaim.; or the equis-*aient of such be employed.

I therefore particnlarly point out and dis tinctiy claim as my invention 1. In a ietliod of indicatingy variationz-; in density oi certain gas, the steps i 'hich con si facing alternating opposing; if" .1d and of another gas ot sub:` antiaiiy ui jing; density upon an element movable ir either direction, and em'ployingl the move ants oi said element to indicate the density et said certain gas.

2. In a .method o indicating?t variations in density of a certain gas, th steps which consist in dir cting; alternating opposing' blasts of said i and of another gas of substantially niivarying density upon an element movable in either direction, employingV the movements of said element to indicate the densitv of said certain gas, and varying the dynamic relation ot one of said blasts with respect to said element.

y 3. In a method of indicating variations in density ot' a carbon-diemcle-containing gas, the steps which consist in directingr alternatino; opposing blasts ot said gras and ot another. gas of substantially unvaiyinf.Y density upon an clement movable in either direction, and translating the resultant of such movements into a visible measuring indication ci' the density of such carbon-dioXide-containing as.

el. In a method of indicating,F variations in density of a carbon-diemde-containing gas, the steps which consist in directing alternating opposing; blasts of said gas and of air upon an element movable in either direction, convertingr the resultant of such movements into a visible measuring indication of the density of such carbon-dioxide-containing' gas, and adjusting the dynamic relation of the blasts ot' such gas by control from the resultant of the movements.

5. In a device of the character described, the combination of opposed nozzles, a member located in the range thereof and movable in either direction, means Whereb the dynamic relation ot one of said nozz es is able in either direction, means whereby the dynamic relation of one of said nozzles is controlled by said member, and means for indicating the resultant of the movements of said member.

7. In a device of the character described, the combination of opposed nozzles, a member located in the range thereof and movable in either direction, means for alternately supplying' to said nozzles respectively a gas to be determined and another gas of constant quality, means whereby the dynamic relation ot the nozzle supplied with the gas to be determined is adjusted under the control of said member. and means for indicating the resultant of the movements of' said member.

8. In a device of the character described, the combination of opposed nozzles, a member located in the rance thereof and rotatable in either direction, means for alternately supplying to said nozzles respectively a ,cias to be determined and another gas of constant quality, means whereby the dynamic relation ot' the nozzle supplied with the gas to be determined is adjusted under the control o't said member. and means for indicating' the resultant of the movements ot said member.

9. in a device ot the character described, the combination of a bladed rotor, blast nozzles located in adjustable opposed dynamic relation thereto, a connection between the rotor and one ot' the opposed nozzles adapted to convert rotation of the rotor into-change of dynamic relation otI the nozzle to the rotor so as to diminish the etl'cct on the rotor of the ict delivered thereto, and means to indicate such change.

10. In a device of the character described, the combination of opposed nozzles.r a bladed rotor located in the range thereof, gearing connected vvith said rotor, a pointer actuated by said gearing', a cam also actuated by said gearing", and connecting means between the cam and one of said nozzles for varying the dynamic relation of the nozzle to the rotor.

1l. In a device of the character described, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected with -said rotor, a pointer actuated by said gearing, means also actuated by said gearing for varying the dynamic relation of one of Said nozzles to the rotor, and means for manually adjusting the opposing nozzle.

12. In a device of the character described, the combination of opposed nozzles, a member located in the range thereof and movable in either direction, means for showing the resultant of the movements of said member, a pump connected to alternately supply said nozzles respectively With a gas to be determined and a gas of constant quality, and

means for equalizing the temperature of the gases supplied.

13. In a device of the character described, the combination of opposed nozzles, a member located in the range thereof and rotatable in either direction, means for showing the resultant of the movements of said member, a pump connected to alternately supply said nozzlesv respectively with a gas to be determined and a gas of constant quality, and` means for equalizing the temperature of the gases supplied.

14. In a device ot' the character described, the combination of opposed nozzles` a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer actuated by said gearing, means also actuated by said gearing t'or adjusting the position of one of said nozzles, a pump connected to alternately supply said nozzles respectively with a gas to be determined and a gas of constant quality, and means for equalizing the temperature of the gases supplied.

15. In a device of the characterdescribed, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer actuated by said gearing, a cam also actuated by said gearing for adjusting the position of one of said nozzles, a pump connected to alternately supply said nozzles respectively with a gas to be determined and a gas ot' constant qnality. and means ior equalizing the temperature of the gases supplied.

16. In a device ot' the character described` the combination ot' opposed nozzles` a bladed rotor located in the range thereof. gearing connected with said rotor. a pointer actuated by said gearing. means also actuated by said gearing l'or adjusting the position of one ot' saidv nozzles, means for manually adjusting the opposing nozzle, a pump connected to alternately supply said nozzles respectively with a gas to be determined and a gas of constant quality, and means for eqnalizing the temperature ofthe gases supplied.

1T. In a device of the character described, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer, and a lost-motion connection between said gearing and said pointer.

18. ln a device of the character described, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer, a lostmotion connection between said gearing and said pointer. and means also actuated by said gearing for adjusting the position of one of said nozzles.

19. -In a device of the character described, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer, a lostmoton connection between said gearing and said pointer, a cam also actuated by said gearing, and a link operated by said cam for adjusting the position of one of said nozzles.

20. In a device of the character. described, the combination of opposed nozzles,''a bladed rotor located in the range thereoftgearing connected with said rotor, a pointer, af'lo'st# motion connection between said gearing and said pointer, a pump connected to alternately supply said nozzles respectively with a gas to be determined and a gas of constant quality, and means for equalizing the temperature ot' the gases supplied.

2l. In a device of the character described, the combination of opposed nozzles, a bladed rotor located in the range thereof, gearing connected With said rotor, a pointer, a lostmotion connection between said gearing and said pointer, means also actuated by said gearing for adjusting the position of one of said nozzles, a pump connected to alternately supply' said nozzles respectively with a gas to be determined and a gas of constant quality, and means for equalizing the temperature of the gases supplied.

QQ. In a device of the character described, the combination of opposed nozzles. a bladed rotor located in the range thereof, gearing connected with said rotor, a pointer, a lostmotion connection betweensaid gearing and said pointer, a cam also actuated by said gear? ing, a link operated by said cam for adjusting the position of one of said nozzles. a pump connected to alternately supply said nozzles respectively with a gas to be determined and a gas of constant quality, and means for equalizing the temperature of the gases supplied.

Signed by me this 24th day of July, 1926.

HERBERTH. DOW. 

